Electric discharge lighting apparatus



Aug. 21, 1956 J. c. MOERKENS 2,760,113

ELECTRIC DISCHARGE LIGHTING APPARATUS Filed Aug. 15. 1952 A TI l i i I INVENTVOR JOZEF CORNELIS MOERKENS P 3 BY 1 V v AGENT United States Pate'fiifO ELECTRIC DISCHARGE 'rierirmenrrnmrns Joiefi. Cornelis" Moerkens,- Eindhoveng Netherlands; as-

signor to {HartfordNational Bank and Trust Company, Hartfrd,-.Conn., astrustee Application August 15,1952, Serial No. 304,505

Claims priority,application-Netherlands- September 1, 1951 3 Claims." ((31. 31"5-'-1-38)" substantially corresponding to unity is obtained. In such apparatus heretofore knownin theart,. the circuit is arranged so' that the tubes, each in series relationship with its respectiveirhpedance, are inparallel with each other across --the lin'e potential. Such 'an arrangement however, has the disadvantage that the apparent power or volt-amperesdissipated bythe impedances is much-too large. Consequently, the impedance musttbe overdesigned to handle this-power so that it becomes underloa'dedfor the actual or real power dissipated.

The main object of the invention is to reduce the apparent power taken by the impedances.

This and other objects of the invention will be best understood from the following description.

According to the invention one of a pair of said electric discharge tubes is connected in series with a capacitative impedance to a source of potential suflicient to ignite the tube and the other tube is connected in series with an inductive impedance across at least a portion of the capacitative impedance to obtain a potential diiference sufficient to ignite the latter tube. With such an arrangement, the apparent power taken by the individual impedances is materially reduced.

The invention will now be described with reference to the accompanying drawing, in which the sole figure shows a circuit diagram of an apparatus according to the invention.

The figure shows an apparatus according to the invention comprising a discharge tube 1 filled with gas or vapor or both, for example, a fluorescent low-pressure mercury vapor discharge tube. The tube 1 is connected by way of a capacitor 2 and an inductor 3 to terminals 4 and 5 of a suitable source of alternating potential (not shown) for operating the tube, e. g., lighting mains at about 220 volts, 50 C. P. S. At the frequency of 50 C. P. S., the capacitative reactance of the capacitor 2 exceeds the inductive reactance of the inductor 3 so that the series-connection of these two elements constitutes a capacitative series-impedance for the tube. The tube itself comprises two activated main electrodes 6, 7 and two conductive ribbon-shaped auxiliary electrodes 8, 9, each of which is connected to one of the main electrodes within the discharge space. The auxiliary electrodes 8, 9 extend parallel to the axis of the tube, within the discharge space, substantially up to the opposite main electrode and are insulated from the latter. Such tubes are often termed tubes with an internal, connected ignition strip. Upon connection to: an appropriate lsourceofpotentiah. a glow discharge .isnproducedl between .a. momentarily negative main..electrode,..as a,.cathode, andv the nearest part of the auxiliary electrode, as. an anode. The glow discharge passes from the main electrode along the auxiliary electrode to..the..other main..electrodexheating it to its emission temperature whereby theglow discharge passes-over into an. arcdischarge...

The apparatus .furt-hercomprises-atseconddischarge tube .10which is connected by way of aninductor 11in parallellwith the capacitative series impedance 2-3. In the figure, the end 12 of-theinductor 11.is connected to the end 13 of the inductor 3. If desired, a tap 14 .or the other end 15 of'inductor 3 may,be.used insteadof 'poirit13l The tube 10 is also constituted by two activated main electrodes 16, 1'7 and .two internal, connectedignition strips or auxiliary electrodes 18, 19.

If the tubes land 10 are, for-example, fluorescent tubes approximately 120, cms. long andapproximately 38 mmsLin diameter, during normal. operation they'willdissipate a power of 40 w. with an operating voltage of approximately 110V. and a current. of approximately 440 ma. and 420"ma., respectively. On applyingia potential between the junction terminals 4 and 5, first the tube I'an'd subsequentlythe tube 10 willignit'e so rapidly that it"will'fon'ly be discernible at allower potential. During normal operation with a main potential of 220 v., a. currentof approximately39'0 ma, flows through the elements 2"a'ndi3,' a voltage of approximately 177 v. occurring across the capacitor Z'and a voltage of about 79 v. occurringacross the inductor 3. The operating current. of thbe'1'0, approximately 420 ma, flows through the. inductor 1j1.-and' the .voltf geacross this inductor is approximately :57 v.

with these currents and ivoltages, the apparent power ofth'e-series elements of the tubes is: Approximately 24 v. a. for inductor 11;

Approximately 30 v. a. for inductor 3; and Approximately 76 v. a. for the capacitor 2,.

The product of the supply potential and the operating current for tube 1 is 220 v. 0.44 a.=97 v. a., and for tube 10 is 220 v. 0.42=93 v. a. Hence, the inductor 11 has an apparent power which is only about 25% of the 93 v. a. The overall apparent power of capacitor 2 and inductor 3 is only about 110% of the 97 v. a.

For purposes of comparison, when the prior art circuit arrangement for the tubes is utilized in which the electrode 17 of tube 10 is not connected to point 20 but to terminal 5, the apparent power of inductor 11 is about of the 93 v. a. and the overall apparent power of the capacitor 2 and the inductor 3 is about 220% of the 97 v. a. Consequently, with the arrangement according to the invention, a substantial reduction of the apparent power taken by the impedances is obtained.

If the supply potential is too low, ignition of tube 10 may not occur. This may be avoided by connecting point 12 of the inductor 11 to a tap, for example, point 14 of the inductor 3,

The term supply potential, as used herein, is to be understood to mean the voltage applied across the leading tube (in this case tube 1) plus its series impedance during operation. As is well-known, this voltage can be given any predetermined value by means of a transformer, for example, if the mains voltage is too low.

As tubes striking without using a switch short-circuiting the tube, besides the aforesaid tubes comprising one or two ignition strips, any tube which is ignited directly by the supply potential or is provided with means for reducing the ignition voltage, for example, by heating the electrodes of the tube to their emission temperature with the aid of transformers, or by increasing the voltage across 3 the tube with the use of a reactive impedance connected in parallel with the tube, may be used in the apparatus according to the invention.

While the invention has been described in connection with specific examples and in specific application, other modifications thereof will be readily apparent to those skilled in the art without departing from the invention as defined in the appended claims.

What I claim is:

1.'An electric discharge apparatus comprising a pair of electric discharge tubes including a first and second tube each having an ionizable gaseous medium and having the characteristic of igniting without using a switch short-circuiting the tube upon application of a given supply potential thereto, a capacitative impedance connected in series relationship with said first tube, said capacitative impedance comprising a capacitor and an inductor connected in series, an inductive impedance connected in series relationship with said second tube, means for connecting said series-connected second tube and inductive impedance in parallel relationship with at least said capacitor and a portion of said inductor, and means for applying said given potential across said first tube and said capacitative impedance.

2. An electric discharge apparatus comprising a pair of electric discharge tube-s including a first and second tube each having an ionizable gaseous medium and having the characteristic of igniting without using a switch short-circuiting the tube upon application of a given supply potential thereto having a frequency of about 50 C. P. S., a capacitative impedance connected in series relationship with said first tube, said capacitative impedance comprising a capacitor and an inductor connected in series, an inductive impedance connected in series relationship with said second tube, means for connecting said series-connected second tube and inductive impedance in parallel relationship with at least said capacitor and a portion of said inductor, and means for applying said given potential across said first tube and said capacitative impedance, said inductive impedance having a value at which it takes an apparent power not more than 0.7 times the product of said supply potential and the current of said second tube, said capacitative impedance having a value at which it takes an apparent power not more than 2.1 times the product of said supply potential and the current of said first tube.

3. An electric discharge apparatus comprising a pair of electric discharge tubes including a first and second tube each having an ionizable gaseous medium and having the characteristic of igniting Without using a switch short-circuiting the tube upon application of a given supply potential thereto having a frequency of about C. P. S., a capacitative impedance connected in series relationship with said first tube, said capacitative impedance comprising a capacitor and an inductor connected in series, an inductive impedance connected in series relationship with said second tube, means for connecting said series-connected second tube and inductive impedance in parallel relationship with at least said capacitor and a portion of said inductor, and means for applying said given potential across said first tube and said capacitative impedance, said inductive impedance having a value at which it takes an apparent power of about 0.26 times the product of said supply potential and the current of said second tube, said capacitative impedance having a value at which it takes an apparent power of about 1.1 times the product of said supply potential and the current of said first tube.

References Cited in the file of this patent UNITED STATES PATENTS 2,025,471 Osborne Dec. 24, 1935 2,314,311 Karash Mar. 16, 1943 2,363,868 Karash Nov. 28, 1944 2,436,399 Nathanson Feb. 24, 1948 2,611,885 Bridges Sept. 23, 1952 

